In a Clinical Trial, 780 Participants Suffering from High Blood

In a clinical trial, 780 participants suffering from high blood pressure were randomly assigned to one of three groups. Over a one-month period, the first group received a low dosage of an Experimental drug, the second group received a high dosage of the drug, and the third group Received a placebo. The diastolic blood pressure of each participant was measured at the beginning And at the end of the period and the change in blood pressure was recorded. Identify the Experimental units (subjects) .

A) The three different groups
B) The treatment (i.e., placebo, low dosage of drug, or high dosage of drug)
C) The participants in the experiment
D) The diastolic blood pressures of the participants